1. Field of the Invention
The invention relates generally to polycarbonate compositions comprising polyalkyl(alkyl)acrylate (co)polymers having a specific molecular weight and an impact modifier, and to moulded bodies obtainable from these compositions. The compositions according to the invention exhibit a good level of properties, in particular in respect of low-temperature impact strength and melt flowability, but also in respect of heat distortion resistance and volatile organic component (VOC) emissions.
2. Description of Related Art
EP-A 0 455 116 describes thermoplastically processable polyalkyl(alkyl)acrylate-containing compositions having improved thermal and mechanical properties and containing from 50 to 90 wt. % polymethyl methacrylate, from 5 to 40 wt. % polycarbonate and from 5 to 40 wt. % of a copolymer with polybutadiene as the strong phase constituent, the polymethyl methacrylate having a molecular weight of over 70,000 g/mol.
JP-A 1991/124764 discloses a non-pearlescent composition containing from 20 to 70 parts by weight aromatic polycarbonate, from 30 to 80 parts by weight polyalkyl(alkyl)acrylate and from 1 to 10 parts by weight of an acrylic polymer having a core-shell structure.
JP-A 1996/085749 discloses compositions having good stability to weathering and good mechanical properties, containing from 5 to 50 parts by weight polyalkyl(alkyl)acrylate, from 30 to 70 parts by weight polycarbonate, from 3 to 30 parts by weight ABS as impact modifier, and from 1 to 20 parts by weight talc of specific geometry.
JP-A 1996/269314 discloses thermoplastically processable compositions which are dimensionally stable under heat and have improved low-temperature impact strength and resistance to weathering and which contain from 1 to 99 parts by weight polycarbonate or polyester carbonate, from 1 to 99 parts by weight polyalkyl(alkyl)acrylate and from 0.5 to 50 parts by weight vinyl-monomer-grafted silicone-alkyl(meth)acrylate polymer composite rubber.
JP-A 1998/007869 discloses thermoplastically processable compositions which are dimensionally stable under heat, impact resistant and stable to weathering and which contain from 10 to 90 parts by weight polycarbonate, from 10 to 90 parts by weight polyalkyl(alkyl)acrylate and from 1 to 50 parts by weight impact modifier.
NL 9002254 describes blends having good low-temperature impact strength, comprising 57 wt. % polycarbonate, 18 wt. % ABS graft polymer and 25 wt. % polyalkyl(alkyl)acrylate having a weight-average molecular weight of 100,000 g/mol.
EP-A 0 463 368 discloses compositions of polycarbonate, PMMA, ABS and a monomeric phosphoric acid ester which are flame-resistant and are distinguished by improved weld line strength.
EP-A 1 592 740 describes flame-resistant compositions having good weld line strength, resistance to chemicals, elongation at break, heat distortion resistance and melt flowability, which contain aromatic polycarbonate, PMMA, styrene-, butadiene- and acrylonitrile-free graft polymer, and organic phosphoric acid ester.
Compositions previously disclosed all tend to contain polyalkyl(alkyl)acrylate having a high weight-average molecular weight—compared with compositions according to the invention—and have inadequate low-temperature impact strength and/or inadequate heat distortion resistance and/or inadequate melt flowability for use in many applications in automotive construction, in particular for components that are relevant in terms of safety.